System to also send tsunami warnings

THREAT ASSESSMENT:：The warning messages would include an estimated time of arrival and wave height according to each mobile phone user’s location, an official said

Staff writer, with CNA

Wed, Nov 15, 2017 - Page 4

Emergency tsunami alerts would be sent to mobile phones through the nation’s Public Warning System after powerful earthquakes strike offshore, the Central Weather Bureau said on Monday.

The tsunami warning will be the latest service offered by the system, which already notifies 4G service subscribes of earthquakes, thunderstorms and typhoons.

Tsunami warnings are to be sent under two scenarios.

The first is when a tsunami is triggered by a distant earthquake and forecast by the Pacific Tsunami Warning Center (PTWC) to reach Taiwan within three hours, the bureau’s Seismology Center said.

The message would include an estimated time of arrival and wave height according to the location of each mobile phone user, center section chief Lin Tzu-wei (林祖慰) said.

Under the second scenario, the system would send alerts when there is a strong offshore earthquake with a shallow focus that could pose a tsunami threat to coastal areas, the bureau said.

Earthquakes with a magnitude of 7 or higher and a depth of less than 35km centered in waters between 20 and 27 degrees north latitudes, and between 118 and 124 degrees east longitudes would trigger alerts, the center said.

The system is to divide Taiwan into six regions: north, northeast, east, southeast, southwest and the Taiwan Strait area, which covers the nation’s west coast and outlying counties.

“The messages will be sent within 10 to 15 minutes in the case of an offshore earthquake to warn people to avoid coastal areas and go to higher places,” Lin said.

The timing for issuing a warning for distant tsunamis is more difficult, because it depends on when the alert is released by the PTWC and the amount of time experts need to figure out its effects on Taiwan, he said.

The tsunami warning system is to send text messages only.

A sound alert accompanies warnings for earthquakes with a magnitude of 5 or higher that have an intensity of three or above in Taipei and four or above in other areas, Lin said.